<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        *{
            padding:0;
            margin:0;
        }
        #app{
            width:100vw;
            height:100vh;
            background:#6ff;
        }
    </style>
</head>
<body>
    
    <?php
        echo "wh2107-天道酬勤";
    ?>
    <div id="app">
        PHP 可以直接书写 HTML CSS JavaScript 
    </div>

    

</body>
</html>